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Mineralized chitin nanocrystals enhance osteoinductive ability of chitosan 3D porous biohybrid scaffolds for bone tissue regeneration
No full textInternational audienceThe loss of alveolar bone due to periodontitis has high worldwide prevalence, and Tissue Engineering (TE) emerges as an alternative to replace autologous bone grafting. Herein, TE fundamentals were applied to mimic bone extracellular matrix (ECM) and cells microenvironment. First, biomimetic hydroxyapatite-based mineralized chitin nanocrystals (MCHNC) from both alpha or beta isoforms were synthesized, showing excellent in vitro biocompatibility and osteoinductive properties over human adipose-derived mesenchymal stem cells (hASCs) osteogenic differentiation. Then, biohybrid 3D porous biomaterials were obtained by combining MCHNC as inorganic nanoparticles, chitosan (CS) as organic matrix and hASCs spheroids. The biohybrids showed an improvement of the mechanical properties over non-mineralized scaffolds. Furthermore, they presented high in vitro biocompatibility and bioactivity, providing an adequate microenvironment for cells. In particular, CS/MβCHNC biomaterial presented the greatest mechanical properties (191 ± 10 kPa). Additionally, the incorporation of MβCHNC provided the biomaterial with osteoinductive character, since hASCs showed increased ALP activity (3.5-fold) and higher matrix mineralization (26.3-fold), even when cultured in standard cell culture medium. Finally, the osteospheroids showed very good integration into the CS/MβCHNC biomaterial, with great migration and colonization of viable cells. These findings demonstrate the potential of CS/MβCHNC biomaterial for TE as alveolar bone regeneratio
Diversity of sea trout marine migration routes in the English Channel
No full textInternational audienceAnadromous brown trout ( Salmo trutta ), also called sea trout, migrate from freshwater nursery and spawning grounds to the sea to maximise their growth and fecundity. Sea trout may undertake this marine migration several times in their life cycle, repeatedly facing significant natural or anthropogenic pressures on their migration path. Using data storage tags, we reveal for the first time the migratory paths and behaviour of post-spawning sea trout from three rivers (two in England and one in France) draining into the English Channel. Our results show a longitudinal gradient in sea trout migratory timing, with individuals from the western population reaching the sea earlier and residing longer in the marine environment than the eastern populations. Overall, sea trout dispersed widely within the English Channel, and each population used distinct marine areas up to the Celtic and North Seas. Within populations, individuals followed one or two directional migration routes that enabled us to identify seven main migratory corridors. Most sea trout spent 80% of their marine phase within 45 km of the shore, with a greater tendency to utilise waters further away from the shoreline at the midpoint of their marine migration. Individual tag data also show that having prior migratory experience influences horizontal behaviours. Finally, individuals from France were geolocated in English waters and vice versa, underpinning the necessity for international management of sea trout around the English Channel
Modelling the distribution of rare and data-poor diadromous fish at sea for protected area management
No full textABSTRACT Anthropogenic pressures have resulted in declines in diadromous fish. Many diadromous fish which were commercially important are now threatened and protected. Little is known about their marine life history phases, and no observation-based Species Distribution Model exists for this group of species at sea. Yet, fisheries dependent and independent data could provide new insights into the distribution of diadromous fish at sea. We collated a database of 168 904 hauls from fisheries observer bycatch data and scientific fisheries surveys, from eastern Atlantic and Mediterranean waters. The distribution of eleven rare and data-poor diadromous fish (shads, lampreys, salmonids, the European eel, the thinlip mullet, smelt and the European flounder) were modelled. A Bayesian site occupancy model, that incorporates imperfect detection to account for repeat detections and non-detections, the non-random nature of fishing gear type and spatial autocorrelation was used. From the model outputs, we explored bycatch risk and the role of MPAs, required under the Marine Strategy Framework Directive and Habitat Directive and assessed. Diadromous fish were observed within relatively shallow coastal areas. Species specific gear bycatch trends were observed. Core distribution areas corresponded to their known water basin presence, indicating connectivity with their freshwater habitats. Numerous Habitat Directive Marine Protected Areas were found to be of relevance. Given the coastal distribution of these species, they are exposed to higher anthropogenic pressures from both terrestrial and marine environments. Risk of bycatch at sea for most species appears to be low. Nonetheless, for threatened individuals, even a small amount of bycatch may impact their populations, especially since misreporting is likely to be high. Differences in catchability between gears highlight potential benefits of limiting access of certain gears within protected areas to reduce bycatch
Écrire avec les genres populaires du cinéma : des effets de la transposition du film noir et du western sur le roman contemporain
No full textInternational audienceThis article considers the tropism of the contemporary novel towards cinema through the prism of filmic genres, focusing on the transpositions of the Western and film noir in a corpus of French and Anglo-Saxon novels published from the late 1990s onwards (Martin Amis, Robert Coover, Christine Montalbetti, Tanguy Viel). In the light of the theory of intermediality (Louvel, 2010, 2014) and studies of cinematic genericity (Altman, 1992), I consider the issues of these intermedial transpositions. If today’s novelists reappropriate filmic conventions of the past, in particular the codes of 1930-1960s Hollywood cinema, it is because they provide ingredients such as typical characters and action scenes, allowing to “renarrativise” (Kibédi-Varga, 1990) the novel. The filmic devices are the the object of an ambiguous rewriting, which highlights the hackneyed nature of film genres or subjects them to a carnivalesque treatment (Bakhtine, 1970), while paying a nostalgic tribute to these legendary modeles.Cet article envisage le tropisme du roman contemporain vers le cinéma au prisme des genres filmiques, en s’intéressant aux transpositions du western et du film noir dans un corpus de romans cinéphiles des domaines français et anglo-saxons parus à partir de la fin des années 1990 (Martin Amis, Robert Coover, Christine Montalbetti, Tanguy Viel). À la lumière de la théorie de l’intermédialité (Louvel, 2010, 2014) et des études de généricité cinématographique (Altman, 1992), l’on considére les enjeux de ces transpositions intermédiales : si les romanciers d’aujourd’hui se réapproprient les conventions filmiques du passé et, notamment, les codes du cinéma hollywoodien des années 1930-1960, c’est notamment parce qu’ils présentent des ingrédients – des personnages hauts en couleur, des scènes d’action rituelles – à même de « renarrativiser » le récit (Kibédi-Varga, 1990). Les modèles filmiques sont alors l’objet d’une réécriture ambiguë, qui met en avant le caractère galvaudé des films de genre ou qui les soumet à un traitement carnavalesque (Bakhtine, 1970), tout en rendant un hommage teinté de nostalgie à ces modèles mythiques
Hybrid Coagulation–Membrane Filtration Techniques for Sustainable Soap Wastewater Treatment
No full textInternational audienceWastewater from soap production often contains high levels of organic pollutants, exceeding regulatory discharge limits and posing significant environmental concerns. This study investigates a two-stage treatment approach integrating ferric chloride (FeCl3)-based coagulation–flocculation with membrane filtration to enhance wastewater purification efficiency. This method is one of the appropriate treatment techniques to reduce water pollution. Thus, numerous Jar test trials have been carried out in order to determine the optimal conditions and parameters that make it possible to reduce suspended solids. Key water quality parameters, including chemical oxygen demand (COD), pH, and turbidity, were monitored to assess process performance. Optimization experiments identified optimal coagulation–flocculation conditions, achieving a substantial COD reduction from 9200 mg/L to 351 mg/L significantly improving water quality. However, the treated effluent still failed to meet reuse standards, necessitating further purification. A subsequent membrane filtration stage was implemented, achieving a significant decrease in turbidity to 0.85 Ntu and a turbidity removal efficiency of 99.97%, indicating high treatment efficiency. The final COD of the collected water was 58 mg/L, well below regulatory limits. This hybrid treatment approach offers a highly effective and sustainable solution for soap wastewater management, supporting environmental protection and resource recovery
Portrait vidéo Lucie Robert
No full text[Portrait] Lucie Robert[Portrait] Lucie RobertQuel est ton parcours ? : 00:21Qu’est-ce que l’occitan ? : 01:08Quel est l’objet de ton travail doctoral ? : 01:54Comment se fait la transmission de l’occitan-limousin ? : 03:00Y a-t-il une volonté politique de préserver l’occitan limousin ? : 04:25Juriste en droit international humanitaire en en droits humains, Lucie Robert a travaillé dans diverses organisations internationales avant de devenir professeure pour les travailleurs humanitaires. Elle s’est alors orientée vers la didactique du français langue étrangère en milieu plurilingue avec une emphase sur les langues minoritaires.Lucie est actuellement doctorante en sociolinguistique et en droit, sous la direction de Véronique Bertile (CERCCLE, Université de Bordeaux) et Giovanni Agresti (IKER, Université de Bordeaux Montaigne).Elle travaille sur l’impact des politiques publiques dans la transmission scolaire et familiale de l’occitan limousin depuis le deuxième après-guerre. Ses travaux portent sur les langues minor(is)ées, la conscience linguistique, les représentations du territoire, l’attachement au parler vernaculaire et le patrimoine linguistique de la zone occitane limousine.Elle a fondé le projet de recherche participative HENRIETTE – Hommage, ENquête, Reproductibilité : Idiome ET Territoire – en hommage à la linguiste Henriette Walter – portant sur la vitalité de l’idiome occitan limousin. Elle a également co-fondé le projet CLAROR – Consciéncia Lingüistica e Analisi de las RepresentaciOns Regionalas analysant les représentations et la conscience linguistique en zone occitane.Lucie Robert porte en 2025, avec un collectif de doctorantes, le projet REconnaissance et Catégorisation des LAngues Minor(is)ées – RECLAM (AAP MSHBx 2025)
A Petro‐Physical Model for Serpentinized Mantle and Origin of Natural Hydrogen in the Pyrenees
No full textInternational audienceAbstract The relationships between the serpentinized continental mantle in orogens, its geophysical signature at depth and hydrogen seepages are poorly understood. A petro‐physical modeling approach accounting for serpentinization shows that a large domain of serpentinized mantle (1,800 km 2 ) is present in the northern Pyrenees. The serpentinization reached a maximum of 40% during the mid‐Cretaceous rifting, according to the predicted temperature and pressure. Although high‐temperature serpentinization could have generated large quantify of hydrogen during the Mesozoic, the shallow and inactive faulting in Northern Pyrenees make this process unlikely to explain the entire serpentinization inferred by petro‐physical modeling. A combination of low‐temperature alteration of mafic and ultramafic rocks in the North Pyrenean Zone, active normal faulting in the North Pyrenean Fault, accumulation in local traps and transport of H 2 ‐rich fluids along inactive but permeable fault may explain the hydrogen seepages observed today
